Abstract

The motion of small spherical particles in three-dimensional flows is studied analytically. in the weak-inertia limit. We obtain analytical results on the motion of heavy and light particles arid the relative importance of the inertia and the Basset force contribution throughout the vortex region for the ABC flow and Hill's vortex. We find that in certain circumstances chaos is suppressed for light or heavy particles advected by the flow. We also find that the Basset force has only a weak effect in the region of a vortex center and gradually becomes mon important near a separatrix; its principal effect is to change the magnitude of the drift of particles towards either a vortex center or a separatrix.